Information processing apparatus, information processing method, and program

Abstract

An information processing apparatus including a first processing unit configured to define an entirety indicated by multiple pixels as a single image, and identify a first histogram that is a histogram of brightness in the image; a second processing unit configured to set an adjustment amount in the first histogram; and a third processing unit configured to subtract, from the first histogram, a portion near a peak of the first histogram, based on the adjustment amount, and shift a histogram corresponding to the portion to an area of the first histogram at which the peak is at least relatively low to generate a second histogram.

What is claimed is: 
     
       1. An information processing apparatus comprising:
 a processing circuitry configured to: 
 define an entirety indicated by multiple pixels as a single image, and identify a first histogram that is a histogram of brightness in the image; 
 set an adjustment amount in the first histogram; and 
 subtract, from the first histogram, a portion of a frequency of an area near a peak of the first histogram, based on the adjustment amount, and increase the frequency of at least an area of the first histogram at which the frequency is relatively low using the subtracted portion of the frequency of the area near the peak, to generate a second histogram. 
 
     
     
       2. The information processing apparatus according to  claim 1 ,
 the information processing apparatus performing signal processing on a first signal indicating a brightness, a second signal associated with a first color, and a third signal associated with a second color, or the first signal, the second signal, the third signal, and a fourth signal associated with a third color, 
 wherein the processing circuitry is further configured to: 
 generate a fifth signal in which a brightness indicated by the first signal has been changed based on the second histogram, 
 change, in a case in which signal processing is to be performed on the first signal, the second signal, and the third signal, in accordance with a change in the brightness, a first color difference signal including a value obtained by subtracting the first signal from the second signal to a first color difference signal including a value obtained by subtracting the fifth signal from the second signal, and change a second color difference signal including a value obtained by subtracting the first signal from the third signal to a second color difference signal including a value obtained by subtracting the fifth signal from the third signal, and 
 generate, in a case in which signal processing is to be performed on the first signal, the second signal, the third signal, and the fourth signal, a first color difference signal and a second color difference signal based on the second signal, the third signal, and the fourth signal, and change the generated first color difference signal and the generated second color difference signal based on a change in the brightness. 
 
     
     
       3. The information processing apparatus according to  claim 2 , wherein:
 in the case in which the signal processing is to be performed on the first signal, the second signal, and the third signal, 
 the processing circuitry is configured to, 
 change, when the fifth signal is generated by changing the brightness of the first signal by multiplication with a prescribed multiple, the first color difference signal based on a ninth signal obtained by subtracting the fifth signal from a signal obtained by multiplying the second signal with the prescribed multiple, and change the second color difference signal based on a tenth signal obtained by subtracting the fifth signal from a signal obtained by multiplying the third signal with the prescribed multiple; and 
 in the case in which the signal processing is to be performed on the first signal, the second signal, the third signal, and the fourth signal, 
 the processing circuitry is configured to, 
 generate, when the fifth signal is generated by changing the brightness of the first signal by multiplication with a prescribed multiple, an eleventh signal and a twelfth signal by multiplying, by the prescribed multiple, each of the first color difference signal and the second color different signal that are generated based on the second signal, the third signal, and the fourth signal. 
 
     
     
       4. The information processing apparatus according to  claim 2 ,
 wherein in generating the fifth signal, the processing circuitry is configured to 
 increase the brightness of the fifth signal as the brightness of the first signal decreases, and decrease the brightness of the fifth signal as the brightness of the first signal increases. 
 
     
     
       5. The information processing apparatus according to  claim 4 ,
 wherein in generating the fifth signal, the processing circuitry is configured to 
 execute, with double precision, operations in the process for increasing the brightness of the fifth signal as the brightness of the first signal decreases, and for decreasing the brightness of the fifth signal as the brightness of the first signal increases. 
 
     
     
       6. The information processing apparatus according to  claim 4 , wherein:
 the brightness of the fifth signal is increased as the brightness of the first signal decreases and the brightness of the fifth signal is decreased as the brightness of the first signal increases by using a retinex method for changing an image by using retinex theory. 
 
     
     
       7. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is further configured to perform a contrast autofocus process by using an image in which the brightness has been corrected based on the generated second histogram. 
 
     
     
       8. The information processing apparatus according to  claim 1 , comprising:
 wherein the processing circuitry is further configured to perform an HDR process based on an image in which the brightness has been corrected based on the generated second histogram. 
 
     
     
       9. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram in which the subtracted portion of the frequency of the area near the peak is distributed to the at least the area at which the frequency is relatively low. 
 
     
     
       10. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram in which the subtracted portion of the frequency of the area near the peak is distributed to the area at which the frequency is relatively low and the area near the peak. 
 
     
     
       11. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram in which the frequency of the at least the area at which the frequency is relatively low is increased equally using the subtracted portion of the frequency of the area near the peak. 
 
     
     
       12. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram in which the frequency of the at least the area at which the frequency is relatively low and the area near the peak are increased equally using the subtracted portion of the frequency of the area near the peak. 
 
     
     
       13. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to subtract, from the first histogram, the portion of the frequency exceeding the adjustment amount of the area near the peak, and increase the frequency of the at least the area at which the frequency is relatively low using the subtracted portion of the frequency. 
 
     
     
       14. The information processing apparatus according to  claim 1 , wherein
 the adjustment amount indicates a value for adjusting a degree of flattening of the first histogram, and 
 the processing circuitry is configured to generate the second histogram that is flattened by shifting the subtracted portion of the frequency of the area near the peak, which is acquired based on the adjustment amount, to the at least the area at which the frequency is relatively low. 
 
     
     
       15. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram in which the frequency of the at least the area at which the frequency is lower than the adjustment amount is increased, using the subtracted portion of the frequency of the area near the peak. 
 
     
     
       16. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate the second histogram by performing a process of subtracting, based on the adjustment amount, the portion of the frequency of the area near the peak of the first histogram and increasing the frequency of the at least the area at which the frequency is relatively low, a plurality of times while changing the adjustment amount. 
 
     
     
       17. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate multiple second histograms based on multiple first histograms of multiple divided images into which the single image is divided, before or after a process of generating the second histogram based on the first histogram of the signal image. 
 
     
     
       18. The information processing apparatus according to  claim 1 ,
 wherein the processing circuitry is configured to generate multiple color difference signals, based on multiple color signals of the multiple pixels, a signal indicating a brightness of the first histogram, and changed signal indicating a brightness of the generated second histogram. 
 
     
     
       19. An information processing method comprising:
 defining an entirety indicated by multiple pixels as a single image, and identifying a first histogram that is a histogram of brightness in the image; 
 setting an adjustment amount in the first histogram; and 
 subtracting, from the first histogram, a portion of a frequency of an area near a peak of the first histogram, based on the adjustment amount, and increasing the frequency of at least an area of the first histogram at which the frequency is relatively low using the subtracted portion of the frequency of the area near the peak, to generate a second histogram. 
 
     
     
       20. A non-transitory computer-readable storage medium storing a program that causes a computer to execute processes, the processes comprising:
 defining an entirety indicated by multiple pixels as a single image, and identifying a first histogram that is a histogram of brightness in the image; 
 setting an adjustment amount in the first histogram; and 
 subtracting, from the first histogram, a portion of a frequency of an area near a peak of the first histogram, based on the adjustment amount, and increasing the frequency of at least an area of the first histogram at which the frequency is relatively low using the subtracted portion of the frequency of the area near the peak, thereby generating a second histogram.